Insecticidal oximes

ABSTRACT

THE OXIMES OF THE FORMULA:   1-R1,2-(NO2-),4-(((R2)N-CYCLOHEXYL)-CH2-O-N=CH-)BENZENE   WHERE R1 IS HYDROGEN OR LOWER ALKYL AND N IS AN INTEGER OF 0-4 WHEREIN EACH R2 INDEPENDENTLY REPRESENTS ALKYL OF 1-4 CARBON ATOMS, WHICH ARE NEW, ARE VALUABLE INSECTICIDES HAVING LOW TOXICITY OT WARM-BLOODED ANIMALS.

United States Patent US. Cl. 260-566 6 Claims ABSTRACT OF THE DISCLOSUREThe oximes of the formula:

(R2)n where R is hydrogen or lower alkyl and n is an integer of 0-4wherein each R independently represents alkyl of 1-4 carbon atoms, whichare new, are valuable insecticides having low toxicity to warm-bloodedanimals.

This invention relates to oximes, their preparation, and compositionscontaining them.

The invention provides the oximes of the formula:

in which R is defined as above, or of its alkali metal, e.g. sodium orpotassium, salt, which may be prepared in situ, with a reactive ester ofthe formula:

in which n and R are defined as above and X represents a reactive esterresidue, such as a halogen atom or a sulphonic ester residue. Thereaction is conveniently effected in an organic solvent such as analcohol (ethanol), a nitrile (acetonitrile) or an amide(dimethylformamide), optionally in the presence of a condensing agentsuch as an alkali metal alkoxide at a temperature between ambienttemperature (20 C.) and the boiling point of the reaction mixture.

The compounds of Formula II may be obtained by the usual methods ofpreparation of oximes from the corresponding aldehydes.

The compounds of Formula III may be obtained from the alcohols of theformula:

in which n and R are defined as above, by usual esterification methods.

The alcohols of Formula IV may be obtained from the benzoic acids oresters of general formula:

COOR V in which n and R are defined as above and R represents a hydrogenatom or an alkyl radical containing 1 to 4 carbon atoms, by the usualmethods of reducing acids and esters to alcohols and benzene tocyclohexane, and particularly by the method of Darling et al., J. Chem.Soc., pp. 1364-8 (1953) for the preparation of3-methyl-cyclohexane-methanol.

The compounds of Formula I have remarkable insecticidal properties,especially against Musca domestica and Tribolium, and acaricidalproperties, especially against Tetranychus urticae, with a markedovicidal activity. Furthermore the compounds of Formula I show very lowtoxicity towards human beings and warm-blooded animals. Compounds ofspecial interest are O-(3-t.butylcyclohexylmethyl) 3 nitro benzaldoxime,0 (3- methyl 5 t.butyl cyclohexylmethyl)-3-nitro-benzaldoxime, O(3,3,5,S tetramethyl-cyclohexylmethyl)-3 nitro-benzaldoximer,O-(3,S-dimethyl-cyclohexylmethyl)- 3 nitro benzaldoxime, andO-(3,3,5,5-trimethyl-cyclohexylmethyl -3 -nitro-b enzaldoxime.

The present invention also provides pesticidal compositions containingat least one compound of Formula I, in association with at least onediluent compatible with the active product or products and suitable foruse in agriculture. Depending on whether the composition is aconcentrate or ready to use, it may contain from to 0.001% by weight ofactive material.

The compositions may be solid, if a solid pulverulent compatible diluentsuch as talc, calcined magnesia, kiesclguhr, tricalcium phosphate, corkpowder, adsorbent charcoal or a clay such as kaoline or bentonite isused. These solid compositions are advantageously prepared by grindingthe active compound with the solid diluent or by impregnating the soliddiluent with a solution of the active compound in a volatile solvent,evaporating the solvent and, if necessary, grinding the product to apowder.

Liquid compositions may be obtained by using a liquid diluent in whichthe compound or compounds of the invention are dissolved or dispersed.The composition may be in the form of a suspension, emulsion or solutionin an organic or aqueous-organic medium. Compositions in the form ofdispersions, solutions or emulsions may contain wetting agents,dispersing agents or emulsifiers of the ionic or non-ionic type, forexample sulphoricinoleates, quaternary ammonium salts or products basedon ethylene oxide condensates, such as the condensates of ethylene oxidewith octylphenol or with esters of fatty acids and anhydrosorbitols. Itis preferable to use agents of the nonionic type because they are notsensitive to electrolytes.

If emulsions are desired, the compounds of the invention may be used inthe form of self-emulsifying concentrates by the method described inExample 2 starting from suitable materials:

B P =163168/0.1 mm. Hg.

Yellow viscous oil.

B.P. i70-175/0.2 mm. Hg.

B.P.= 185-189/0.2 mm. Hg.

containing the active substance dissolved in the dispersing agent or ina solvent which is compatible with the said agent, simple addition ofwater making it possible to obtain compositions ready for use.

The compounds of Formula I are preferably used at the rate of 5 to 150g. of active material per hectolitre of water but lower concentrationsmay also be used.

The following examples illustrate the invention.

EXAMPLE 1 20 cc. of a 2.25 N solution of potassium ethoxide in ethanolare added to a suspension of 7.5 g. of 3-nitrobenzaldoxime in 30 cc. ofethanol. 7.9 g. of cyclohexylmethyl bromide are then added dropwise inabout 2 minutes. The mixture is heated for 1 hour under reflux. Aftercooling, the precipitate of potassium bromide is filtered. ofi, and thesolvent is evaporated. The residual oil g.) is taken up in 100 cc. ofmethylene chloride. The resulting solution is washed first with 50 cc.of N aqueous sodium hydroxide solution and then twice with 50 cc. ofwater, and dried over anhydrous sodium sulphate in the presence ofdecolorising charcoal. After filtration and evaporation of the solvent,the resulting oil (9 g.) is distilled under reduced pressure. 7 g. ofO-cyclohexylmethyl- 3-nitrobenzaldoxime, B.P. 155-160 C./0.2 mm. Hg,M.P. 56 C. (Kofler bench) are obtained.

Cyclohexylmethyl bromide (P.B. 8485.5 C./ 30 mm. Hg) is prepared by theprocess of Hiers et al., J. Amer. Chem. Soc. 48, 2389 (1926).

EXAMPLE 2 20.1 g. of 3-rnethylsulphonyloxymethyl-l-methyl-cyclohexaneare added to a suspension of g. of the potassium salt of3-nitrobenzaldoxime in 200 cc. of dimethylformamide. The mixture isheated for 2 hours at 55 C. The greater part of the solvent is thenevaporated under reduced pressure. The residue is taken up in a mixtureof 250 cc. of methylene chloride and. 100 cc. of N aqueous sodiumhydroxide solution. The methylene chloride solution is separated, washedsuccessively with 100 cc. of N aqueous sodium hydroxide solution andwith 250 cc. of water, and dried. over anhydrous sodium sulphate in thepresence of decolorising charcoal. After filtration and evaporation ofthe solvent, the residual oil is distilled under reduced pressure. 19 g.of O-(3-methyl-cyclohexylmethyl)-3-nitrobenzaldoxime, B.P. 165-167C./0.1 mm. Hg, are obtained.

The 3 methylsulphonyloxymethyl-l-methyl-cyclohexane (B.P. 101-111 C./0.1mm. Hg) was prepared by reaction of methanesulphonyl chloride with3-methyl-cyclohexylmethanol in methylene chloride in the presence ofanhydrous triethylamine. The 3-methyl-cyclohexylmethan01 startingmaterial (B.P. 99-100 C./23 mm. Hg) is prepared by the process ofDarling et al., J. Chem. Soc. 1364-8 (1953).

EXAMPLES 3 TO 19 The following compounds of Formula I are prepared CirEXAMPLE 20 5 g. of a condensation product of octylphenol and eth yleneoxide containing 10 molecules of ethylene oxide per molecule ofoctylphenol are added to 20 g. of O-(3- t.butyl cyclohexylmethyl) 3nitrobenzaldoxime, and a mixture of equal volumes of toluene andacetophenone is added until the total volume is cc. The solution is,after suitable dilution with water, used to destroy mites.Concentrations of 5 to 100 g. of active material per hectolitre,depending on the desired effect, give good results.

EXAMPLE 21 400 g. of kaolin, 100 g. of ground gum arabic and 100 g. ofcalcium lignosulphite are added to 400 g. of O-(3-t.butyl-cyclohexylmethyl) 3 nitrobenzaldoxime. After grinding andsieving, the resulting powder is used to protect plants against theattacks of mites, using it after dilution with water at the rate of 250g. of power per 100 litres of water.

The acaricidal activity of the compounds of Formula I was demonstratedin the following test. French bean plants are soaked for 10 seconds inan emulsion of the compound under test. When they are dry, they areintested with red spiders. Mortalities are assessed after 4 days.

Emulsifiable concentrates are prepared having the following compositionAqueous emulsions containing 0.1%, 0.05%, 0.02% and 0.01% of the activecompound. are prepared from these concentrates by dilution with water.

The results obtained are given in the table below.

TABLE Percent mortality 0. 01% 0. 02% 0. 05% 0. 1% Product of ExampleNo. emulsion emulsion emulsion emulsion 5 I claim: 1. An oxime of theformula:

in which R represents hydrogen or alkyl of 1 to 3 carbon atoms and n isan integer of 0-4 wherein each R independently represents alkyl of 14carbon atoms.

2. An oxime according to claim 1 which is O-(3-t.buty1-cyclohexylmethyl) -3-nitro -benza1doxime.

3. An oxime according to claim 1 which isO-(3-methyl-5-t.buty1-cyclohexylmethyl)-3-nitro-benzaldoxime.

4. An oxime according to claim 1 which is O-(3,3,5,5- tetramethyl-cyclohexylmethyl) -3 -nitro-benza1doxime.

5. An oxime according to claim 1 which isO-(3,5-dimethyl-cyclohexylmethyl -3 -nitro-benzaldoxime.

6. An oxime according to claim 1 which is O-(3,3,5-trimethyI-cyclohexylmethyl -3 -nitro-benza1doxime.

References Cited Beilsteins Handbuch der Organischen Chemie, vol. 7, p.903 (1968).

BERNARD HELFIN, Primary Examiner G. A. SCHWARTZ, Assistant Examiner US.Cl. X.R. 424327

